Nowadays, saving energy resources in various fields is becoming a major concern among people, and this trend is also growing in the field of power supplies. More specifically, there is an increasing demand that switching power supplies become even more efficient.
A switching power supply serves to convert an input direct current (DC) voltage into a desired DC voltage by using a DC-DC converter and to output the converted DC voltage as a stabilized power supply voltage. As the voltage is becoming lower and the power consumption is becoming larger in a power supply, as a semiconductor device, such as a central processing unit (CPU), used in a computer, a switching power supply that is able to output a low voltage and a large current is coming into use.
The following is reference document:    [Document 1] Japanese Laid-open Patent Publication No. 11-220874